characteristics

Soil Depth: Approximately 4 ¼”
Module Size (plastic): 1′ x 2′ x 3-¼”
Saturated Weight: Approximately 29 lbs per square foot
Dry Weight: Approximately 20 pounds per square foot*

What it is

The Standard System is the workhorse, used on 80% or more of LiveRoof projects. At 4.25 inches of soil, it is the popular choice for most new construction projects and many retrofits. With saturated weight of 27-29 lbs/sq ft, it is the perfect convergence of functional merits, cost and versatility.

What it does

It provides exceptional storm water management, significant energy savings—even more if irrigated during the warm season. It is commonly used to meet green space requirements, provides modest biodiversity, supporting pollinators such as butterflies and honeybees, and will grow a palette of beautiful low maintenance plants—broad enough for both simple and relatively intricate designs. On top of this, the Standard System can seamlessly transition to the Deep and Maxx Systems without need for edging in between.

What plants work

The type of plants used in the Standard System include a full array of low to tall growing sedums—from fine to very coarse-textured, green, yellow, blue, maroon and multi-colored. Flowers range from white, yellow, pink or purple. Alliums of all sizes are compatible and with regular irrigation a few a low-growing grasses such as little bluestem or prairie dropseed are possible, as are a few broad leaved non-succulent perennials.

How it looks

Because Sedum plants range from fine- to very coarse-textured, and very short to quite tall, the look can vary according to the needs of the project. If one wants a fine-textured moss-like look it can be accomplished easily. But, course-textured and prairie-like are doable as well. Broad expanses are often planted, and more intricate patterns are done as well.

What it needs

With 4 ¼ inches of soil, the Standard System has pretty good water holding capacity, at least for succulent plants. But, when the summers are hot, it can dry down to the point where even Sedums need irrigation. And, given that climates everywhere are warming, we recommend irrigation as an inexpensive insurance policy—at least on moderate to large roofs. And, while many Standard Systems are installed without built-in irrigation, we are strong proponents of having a built-in irrigation system. It’s cheap insurance and by watering occasionally, once per week with 1 inch of water, you can keep your plants thick and lush even through drought and heat—this makes maintenance easy and it looks nice. What’s more, if you keep some moisture in the soil, you will optimize evaporative cooling and save substantially on cooling costs. In any geographic area that has access to irrigation water, this is a win-win scenario, in respect to energy and resource savings.

Other than that, soil fertility should be managed attentively; typically one application of high quality sulfur coated fertilizer each spring is sufficient. LiveRoof’s Smart Weeding™ method should be followed regardless of geography (this is where the maintenance person takes a short “weed walk” every two weeks during the growing season—thus preventing the few baby weeds from growing up and having offspring).

How it’s grown

The base succulent plants are usually started from an assortment of cuttings that are mixed together, applied to the soil surface, and grown to maturity in the nursery setting. Occasionally, particularly if the designer is looking for something unique, the plant palette can be started from a combination of Sedum cuttings and plugs. Accent plants are typically planted from plugs or divisions.

In any event, each Standard System project is delivered fully grown (a process that typically takes 8 to 12 weeks depending upon climate and plant selections).

Comparative cost

The Standard System is economical and will vary somewhat with the plant selections. It usually grows quickly, and installs very easily and quickly as well.